This invention concerns a device for supporting a connection apparatus of the type often used in the oilfield industry for connecting tubular members in sealed relationship. These connection apparatuses are referred to as "clamps" and are used in a variety of applications such as connecting valves to outlets of wellhead housings, connecting wellhead housings in series in vertical relationship and connecting large pressure control devices known as blowout preventers in end-to-end relationship. These clamps are preferred over conventional bolted flange connections in many situations as they require a fewer number of bolts to be tightened and are therefor usually quicker to install or remove.
In the larger sizes however, these clamps are heavy and unwieldy and require some additional means for supporting them in a preferred position during installation. Previously, such means have included ad hoc methods as supporting the clamps with a fork truck or using various rigging arrangements with cables or straps supported by whatever hoisting equipment was available. These methods have proven unacceptable as the surrounding structure of the wellhead or blowout preventer interfered with the rigging arrangement or use of the fork truck. Additionally, these installations must often be done in hostile weather environments or underwater which impose even more problems in handling these large connecting structures.
This invention is for an apparatus which supports a clamp on one hub of a clamp type connection to facilitate installation and removal of the clamp. The invention also has a unique configuration for the bolts used to hold the clamp in its clamped position which allows a greater number of smaller bolts to be used on a clamp of conventional configuration. This use of smaller bolts allows lighter, easier to handle wrenching means to be used.
Prior clamp connections include the J. D. Watts et al. U.S. Pat. No. 2,766,829 which discloses a clamp of the type whose installation the present invention is intended to facilitate. A seal ring typically used with this type of connection is also disclosed.
The R. L. Crain et al. U.S. Pat. No. 3,403,931 shows a modification to the clamp of Watts whereby an axially extending shallow groove is cut in the clamp halves to allow flexure of the clamp body to better distribute the stresses developed in the clamp body during installation.
Another form of clamp connection is disclosed by B. Saunders in U.S. patent application Ser. No. 07/458,957 filed Dec. 29, 1989 now U.S. Pat. No. 4,984,830 and assigned to the same assignee as the present application. This clamp connection uses a plurality of collet segments urged into engagement with hubs configured to receive them by a pair of cam rings operated by axially disposed bolting means. No means for holding the segments or cam rings during installation or removal is disclosed.